.status a:not([href^="https://friends.nico/"]) .display-name:before {
content: '【連合】';
}

.status a[href^="https://mstdn.jp/"] .display-name:before {
color:#A00;
content: '【JP】';
}

.status a[href^="https://friends.nico/"] .display-name:before {
color:#0A0;
content: '【ニコ】';
} https://friends.nico/media/1Zcnb9WT4EE35B85bnI